Cammed terminal clamp for a battery cable



p 1957 J. E. WILSON, JR 2,807,000

CAMMED TERMINAL CLAMP FOR A BATTERY CABLE Filed Jan. 25, 1956 42 Fig. 5

INVENTOR. John E. W/'/s0n,Jr.

ATTQR/VEY Patented Sept. 17, 1957 iice CAMIVIED TERNDNAL CLAIVIP FOR A BATTERY CABLE John E. Wilson, Jr., Muskegon, Mich. Application January 25, 1956, Serial No. 561,193

Claims. (Cl. 339-236) This invention relates to a terminal clamp for a battery cable preferably of the type used on automobiles.

Present day terminal clamps for battery cables are constructed of a cast and highly conductive metal such as copper. The clamps are formed of two jaws having clamping portions which clamp about the post of the battery and flanges extending from the free ends of the clamping portions. Heretofore, a conventional bolt With a nut on the end has been used to force the two flanges together for drawing the clamping portions tightly against the battery post. The disadvantage of this type of clamping action is that it requires screwing of the nut on the bolt which usually requires several turns before the jaws are clamped securely on the post.

This clamping operation involving tightening the nut is sometimes annoying and time consuming especially when the battery is located in a position where the nut is dilficult to turn. Invariably, the cable or clamp obstructs the tool for turning the nut, making it even more dificult. Frequently, the clamp is not secured sufliciently tight on the battery posts because of the inherent binding and frictional forces on the nut makes it diflicult to determine the number of times necessary to tighten the clamp. The only way to determine the tightness is to test whether the clamp can be easily pried from the post with a screw driver or other instrument. This test is not fool proof because in prying the clamp from the post it binds on the post and appears to be secured thereto although in reality the contact between the post and the clamp is not sufliciently tight to give good contact. A loose contact between the clamp and the post is obviously undesirable.

An object of this invention is to provide a terminal clamp having means for quickly securing a clamp to a battery post.

Another object of this invention is to provide a terminal clamp for a battery, the means for tightening such clamp positively assuring a good contact between the clamp and the post.

Still another object of this invention is to provide a terminal clamp for a battery cable, such clamp having means for assuring a positive pressure on the battery post.

A further object of this invention is to provide a cam means for tightening a terminal clamp for a battery, such cam means requiring less than one turn for connecting the clamp on the battery post.

A further object of this invention is to provide a terminal clamp for a battery cable, such clamp having cam means which not only tightens the jaws of the clamp but exerts a pressure on the clamping surface whereby a positive and more tight contact is established between the post and the clamp.

Other objects of this invention will become. obvious upon reading the following specifications in conjunction with the accompanied drawings wherein:

Fig. 1 is a plan view of the terminal clamp for a battery cable.

Fig. 2 is a side, elevational view of one form of stud or bolt with cam means for use in the clamp of Fig. 1.

Fig. 3 is a side, elevational view of another stud or bolt with cam means for use in the clamp of Fig. 1.

Fig. 4 is a side, elevational view of still another form of stud or bolt with cam means for use in the clamp of Fig. 1.

Fig. 5 is an end view of the clamp taken along the plane VV of Fig. 1.

Fig. 6 is a cross sectional view taken along the plane VI-VI of Fig. 1.

Fig. 7 is a cross sectional view taken along the plane VIIVII of Fig. 1.

Briefly this invention is concerned with a terminal clamp for a battery cable. A part of this clamp is of conventional design and includes a pair of opposed jaws adapted to clamp on a battery post. The jaws have a clamping portion defining an opening for a battery post. Opposed spaced flanges are integral with and extend from the clamping portions. The improvement includes a stud or bolt passing through apertures in the flanges, such stud or bolt having cam means for forcing the flanges toward each other thereby causing the clamp to close. In the preferred form of this invention the exterior wall of the clamping portions has a groove in which a working surface of the cam means fits. Upon rotation of the cam means, the cam forces the flanges together and at the same time forces the wall of one of the clamping portions radially inwardly.

Referring to the drawings, Fig. 1 shows a battery cable 10 of the metallic braided type. The cable 10 is secured to the clamp 20 by any suitable means such as a tongue and groove arrangement.

The clamp 20 includes a base 21 secured to the braided cable 10. Extending from the base 21 are two opposed jaws 22 and 23. laws 22 and 23 are adapted to be clamped about a battery post "for connecting the cable 10 to the battery.

Jaw 22 includes a clamping portion 24 and a flange 25 extending therefrom. Jaw 23 includes the clamping portion 26 and the flange 27. As shown in the drawings the clamping portions 24 and 26 define an opening 28 for receiving a battery post. The flanges 25 and 27 extend from the clamping portions and are opposed and parallel to each other. Thus, when forced towards each other, the flanges effect a clamping action by the clamping portions 24 and 26. This construction described thus far is conventional and can be fabricated of conventional material.

The flanges 25 and 27 have the apertures 29 and 30, respectively, for receiving the stud or bolt 41.

The present day method of forcing the two flanges 25 and 27 together to effect a clamping action by the clamping portions 24 and 26, is to provide a common bolt having a threaded end with a nut thereon. The bolt and nut are arranged so that when the nut is tightened it forces the two flanges 25 and 27 together.

In accordance with this invention I have provided a cam means for forcing the two flanges together. This cam means, in conjunction with the flanges and also with one of the clamping portions 26, provides a more positive clamping action, assuring that the clamp is tightly secured to the post and at the same time giving a more positive contact between the clamp and the post.

This cam means includes the post or stud 41 having on one end a hexagonal or other shaped head which is adapted to be gripped by a conventional tool for turning the same. Immediately adjacent the head 42 is the cam portion 43. The cam portion 43 has a working face 44 inclined at an angle to the surface 31 of flange 27 on which surface the working face 44 normally rides. The cam portion 43 also has a Working edge 45 protruding radially from the post 41. The working edge 45 extends beyond the marginal edges of head 42.

Working edge 45 cooperates with a groove 32 formed at the, juncture of the flange 27 and the clamping portion 26. Groove 32 is inclined upwardly (Fig. 6) so that it is deeper at the top than at the bottom. This shape is provided so that the groove will initially receive the working edge 45 but upon further turning of the head 42 and cam 43 the working surface 45 will engage the wall of the groove forcing the clamping portion 26 radially inwardly. At the same time, the working face 44, which is inclined at an angle to the plane of the flange face 31, engages another part of the groove. This forces the flanges 25 and 27 toward each other. The exact configuration of groove 32 and of cam portion 43 can be varied in accordance with the exact position of the groove and the cam portion. They can also vary with the size of the flanges 25 and 26 and the position of the stud 41 extending therethrough.

In the broadest aspect of this invention the shape of the cam and its relationship to the jaws of the clamp is such that a force as illustrated by the dotted arrow A (Fig. l) is exerted on the flanges tending to close the flanges. In the preferred form of this invention the shape of the cam 43 and the arrangement of groove 32 is such that the cam forces the flanges 25 and 27 together and at the same time exerts a force on one of the clamping portions 26 as illustrated by the dotted arrow B (Fig. 1).

The cam means for closing the clamp 20 can take several forms. In Fig. l is shown the preferred form described above. The end of the post or stud 41 is peened over at 4-5. This peened end 46 can be a threaded end as shown in Fig. 2. Such form may sometimes be desirable because as the head 42 is turned or rotated the nut on the head of the stud 41a also tightens resulting in a tighter connection.

Both forms of Figs. 2 and 4 show the cam 43 integral with the stud 41 and head 42. In a broader aspect of this invention, this is not essential. A separate cam element 43a as shown in Fig. 3 can be substituted for the integral cam elements 43. Cam element 43a is shaped like heads 42 so that it can be directly manipulated by any conventional tool. The cam element 43a preferably rotates relative to the post 4111. In many cases, however, it is prevented from rotating due to the frictional force created at the head 42b and at the face 31 of flange 27. In this particular form, element 43a may be made integral with the stud 42b in somewhat the same manner as the form of Figs. 2 and 4.

7 Operation The operation of this clamp is very simple. It has many advantages over a conventional type terminal clamp. The clamp is first opened by turning or rotating the head 42 with any conventional tool such as a pliers or Wrench. This turning movement is in a direction which will disengage the working edge 45 and working face 44' from the walls of the groove 32. Turning the head in this direction permits the flanges, which are normally biased outwardly due to the inherent resiliency of the metal, to spring outwardly and open the jaws 22 and 23. Having opened the clamp, the clamp is placed on a battery post so that the opening 28 receives the post. Then by a simple manipuiation or turning of the head 42 in the opposite direction, the working face 44 and working edge 45 engage the walls of the groove 32. The working face 44 forces the flange 27 in a direction as indicated by the dotted arrow A (Fig. 1); At the same time the Working edge 45 forces the clamping portion 26 in a direction as indicated by the dotted arrow B. This clamping action is accomplished by less than a complete turn of the head 42. In fact the shape of the cam 43 and the groove 32 can be made so that an extremely small degree of rotation of head 42 will result in the clamping action. The degree of rotation depends upon the mechanical advantage desired. The greater the mechanical advantage desired the greater degree of rotation.

It is evident that with the application of forces in directions indicated by arrows A and B, a more positive clamping action on the post results. It should be equally evident that with this mechanism a positive contact between the clamp 22 and the post is assured whereas with a conventional nut and bolt arrangement there is always left some doubt as to whether the nut has been screwed on sufiiciently tight to give the required positive contact between the clamp and the post.

This small degree of rotation of the head 42 made possible by this invention makes the connecting operation for the cable 10 quicker and less diflicult.

The clamp of this invention is no larger than the standard cable clamp. It can be fabricated in the same way as other clamps. For example the clamp 20 including the jaws 22 and 23 and the base 21 can be cast as an integral unit in the same way as present day cable clamps. The only difference is that the mold for the clamp has to include the groove 32 which has little effect upon the overall cost of manufacture. Since the clamp of this invention is similar to a conventional one, the clamp can fit on any standard cable and it is interchangeable with present day equipment. The clamp does not require any special tools and ordinary pliers will work satisfactorily.

Having described my invention it should be understood 1 that although I have shown preferred embodiments and modifications, these embodiments and modifications can be changed without departure from the spirit of this invention. Therefore all modifications or changes made in the specific clamp shown and described herein shall be considered covered by this invention unless the appended claims expressly state otherwise.

I claim: 7

1. In a terminal clamp for a battery cable; said clamp having two opposed jaws; said jaws having clamping portions adapted to clamp about a battery post; opposed spaced flanges extending from said clamping portions; the improvement comprising: rotatable cam means having working surfaces adapted to force said flanges and said clamping portions toward each other to cause said jaws to move from an open position to a clamping position on said battery post said working surface including a working edge engaging said clamping portion and forcing the wall of said clamping portion against said post.

2. In a terminal clamp for a battery cable; said clamp having two opposed jaws; said jaws having clamping portions adapted to clamp about a battery post; opposed spaced flanges extending from said clamping portions; aligned apertures in said flanges; a bolt extending through said apertures; the improvement comprising cam means rotatable about the axis of said bolt and having a working face extending axially of said bolt and adapted to force said flanges and clamping portions toward each other; said cam means also having a working edge extending radially of said bolt and adapted to engage one of said clamping portions whereby said clamping portion is additionally forced against said post in a direction at an angle to the axis of said bolt whereby said one clamping portion is forced radially inwardly.

3. In a terminal clamp for a battery cable; said clamp having two opposed jaws; said jaws having clamping portions adapted to clamp about a battery post; opposed spaced flanges extending from said clamping portions;

aligned apertures in said flanges; a bolt extending through said apertures; the improvement comprising cam means rotatable about the axis of said bolt and having a working face extending axially of said bolt and adapted to force said flanges and clamping portions toward each other; said working face being shaped to effect, in less than one revolution of said means about the axis of said bolt, the closing of said jaws from open position; said cam means also having a working edge extending radially of said whereby said clamping portion is additionally forced against said post in a direction at an angle to the axis of said bolt whereby said one clamping portion is forced radially inwardly.

4. A terminal clamp for a battery cable; said clamp having two opposed jaws; said jaws having a pair of arcuate shaped clamping portions adapted to clamp about a battery post; opposed spaced flanges extending from said clamping portions; aligned apertures in said flanges; a stud extending through and rotatable in said apertures; a cam on one end of said stud; said cam having a working face with a protruding portion extending axially of said stud; said cam also having a working edge with a protruding portion extending radially of said bolt; said Working face and edge having a cooperative relationship whereby when said stud is rotated said working face forces said flanges toward each other and said working edge forces one of said clamping portions radially inwardly effecting a tight clamping action of said clamp about said post.

5. A terminal clamp for a battery cable; said clamp having two opposed jaws; said jaws having a pair of armate shaped clamping portions adapted to clamp about a battery post; opposed spaced flanges extending from said clamping portions; one of said jaws having a groove in the exterior surface thereof in proximity to the juncture of its flange and clamping portion; aligned apertures in said flanges; a stud extending through and rotatable in said apertures; a cam on one end of said stud; said cam having a working face with a protruding portion extending axially of said stud; said cam also having a working edge with a protruding portion extending radially of said belt; said carn being adapted to enter said groove upon rotation of said stud whereby said working face exerts a force on said jaw in a direction substantially parallel to the axis of said stud and said working edge exerts a force on said jaw in a direction at an angle to the axis of said stud efiecting a tight clamping action of said clamp about said post.

Reig May 4, 1954 Lartz Nov. 6, 1956 

